A Summary of the Building Owners And Managers Association (BOMA) Guidelines The purpose of the Standard Method For Measuring Floor Area in Office Buildings is to permit communication and computation on a clear and understandable basis. The BOMA Standard has been the generally accepted method for measuring office space for many years. It should be noted that this standard can and should be used in measuring office space in old as well as new buildings. It is applicable to any architectural design or type of construction. Usable Area This method measures the actual occupiable area of a floor or an office suite and is of prime interest to a tenant in evaluating the space offered by a landlord and in allocating the space required to house personnel and furniture. The amount of Usable Area on a multi-tenant floor can vary over the life of a building as corridors expand and contract and as floors are remodeled. Usable Area can be converted to Rentable Area by the use of a conversion factor. The Usable Area of an office shall be computed by measuring to the finished surface side of the office side of corridor and other permanent walls, to the center of the partitions that separate the office from adjoining Usable Areas, and to the inside finished surface of the dominant portions of the permanent outer building walls. No deduction shall be made for columns and projections necessary to the building. The Usable Area of a floor shall be equal to the sum of all Usable Areas on that floor. Rentable Area This method measures the tenant's pro-rata portion of the entire office floor, excluding elements of the building that penetrate through the floor to areas below. The Rentable Area of a building is fixed for the life of a building and is not affected by changes in corridor sizes and configuration. This method is therefore recommended for measuring the total income producing area of a building and for use in computing the tenant's pro-rata share of a building for purposes of rent escalation. The Rentable Area of floor area shall be computed by measuring to the inside finished surface of the dominant portions of the permanent outer building walls, excluding any major vertical penetrations of the floor. No deduction shall be made for columns and projections necessary to the building. The Rentable Area of an office on the floor shall be computed by multiplying the Usable Area of that office by the quotient of the division of the Rentable Area of the floor by the Usable Area of the floor resulting in the R/U Ratio. Load Factor The Load Factor is the percentage of space on a floor that is not usable, expressed asa percent of Usable Area. It is also known as the Common Area Factor or the Loss Factor. Rentable Area ÷ Usable Area = R/U Ratio -------------------------------------------------------------------------------- Conversion Formulas Load Factor (Load) R/U Ratio - 1 Usable Area x R/U Ratio Rentable Area Rentable Area ÷ R/U Ratio Usable Area Usable Area x (1 + Load) Rentable Area -------------------------------------------------------------------------------- Definitions Finished Surface: A wall, ceiling, or floor surface, including glass, as prepared for tenant use, excluding the thickness of any special surfacing materials such as paneling, furring strips and carpet. Dominant Portion: That portion of the inside finished surface of the permanent outer building wall which is 50% or more of the vertical floor to ceiling dimension measured at the dominant portions. If there is no dominant portion, or if the dominant portion is not vertical, the measurement for area shall be to the inside finished surface of the permanent outer building wall where it intersects the finished floor. Major Vertical Penetrations: Stairs, elevator shafts, flues, pipe shafts, vertical ducts, and the like, and their enclosing walls, which serve more than one floor of the building, but shall not include stairs, dumb-waiters, lifts, and the like, exclusively serving a tenant occupying offices on more than one floor. Tenants' Rules of Thumb The general rule of thumb is to allow 175 to 250 usable square feet per person depending upon the type and style of the business. This figure can vary based upon special needs such as extra-large conference rooms or storage requirements, but will include normal amenities within a general use office. For an accurate determination of space requirements, an office space planner should be consulted. The following standards can be used to help estimate the amount of usable space required for your business. Typical President' s office or Chairman of the Board 250 to 400 sq. ft. (4 to 5 windows in length) Typical Vice-President' s Office 150 to 250 sq. ft. (3 to 4 windows in length) Typical Executive' s Office 100 to 150 sq. ft. (2 widows in length) Partitioned Open Space Clerical Supervisor or Manager 80 to 110 sq. ft. Open Space Clerical or Secretary 60 to 110 sq. ft. Conference Rooms 15 sq. ft. per person: theater style 25 to 30 sq. ft. per person: conference seating Mail Room 8 to 9 ft. wide with 30" counters on either side. Length depends upon amount of usage Reception Area 125 to 200 sq. ft. Receptionist and 2 - 4 people 200 to 300 sq. ft. Receptionist and 6 - 8 people File Room 7 sq. ft. per file with a 3' to 4' aisle width Library Allow 12" for bookshelf width 175 to 450 sq. ft. with seating for 4 - 6 Lunch Rooms 15 sq. ft. per person, not including kitchen. Kitchen should be 1/3 to 1/2 of seating area Clerical Pool Areas 80 to 100 sq. ft. per person Corridors 20% to 30% of the total usable area Coat Closets 1 lineal ft. for 4 coats 3 per person Water Coolers/Drinking Fountains 1 unit per 75 employees Suggested Column Spacing 28' to 30' per bay Suggested Window Mullion Spacing 4'6" to 5'. This determines office width